Bushmeat hunting is extensive in west and central Africa as both a means for subsistence and for commercial gain. Commercial hunting represents one of the primary threats to wildlife in the region, ...and confounding factors have made it challenging to examine how external factors influence the commercial bushmeat trade. Bioko Island, Equatorial Guinea is a small island with large tracts of intact forest that support sizeable populations of commercially valuable vertebrates, especially endemic primates. The island also has a low human population and has experienced dramatic economic growth and rapid development since the mid-1990's. From October 1997 - September 2010, we monitored the largest bushmeat market on Bioko in Malabo, recording over 197,000 carcasses for sale. We used these data to analyze the dynamics of the market in relation to political events, environmental legislation, and rapid economic growth. Our findings suggest that bushmeat hunting and availability increased in parallel with the growth of Equatorial Guinea's GDP and disposable income of its citizens. During this 13-year study, the predominant mode of capture shifted from trapping to shotguns. Consequently, carcass volume and rates of taxa typically captured with shotguns increased significantly, most notably including intensified hunting of Bioko's unique and endangered monkey fauna. Attempts to limit bushmeat sales, including a 2007 ban on primate hunting and trade, were only transiently effective. The hunting ban was not enforced, and was quickly followed by a marked increase in bushmeat hunting compared to hunting rates prior to the ban. Our results emphasize the negative impact that rapid development and unenforced legislation have had on Bioko's wildlife, and demonstrate the need for strong governmental support if conservation strategies are to be successful at preventing extinctions of tropical wildlife.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Island Biogeography Reveals the Deep History of SIV Worobey, Michael; Telfer, Paul; Souquière, Sandrine ...
Science (American Association for the Advancement of Science),
09/2010, Letnik:
329, Številka:
5998
Journal Article
Recenzirano
Simian immunodeficiency virus (SIV) lineages have been identified that are endemic to Bioko Island. The time the island formed offers a geological time scale calibration point for dating the most ...recent common ancestor of SIV. The Bioko viruses cover the whole range of SIV genetic diversity, and each Bioko SIV clade is most closely related to viruses circulating in hosts of the same genus on the African mainland rather than to SIVs of other Bioko species. Our phylogeographic approach establishes that SIV is ancient and at least 32,000 years old. Our conservative calibration point and analyses of gene sequence saturation and dating bias suggest it may be much older.
Bushmeat hunting is among the principal threats to larger-bodied vertebrate species, such as primates, in central Africa. However, species vary in their response to differing levels of hunting ...intensity, making it difficult to not only quantify the effect hunting has on wild populations, but also to plan for effective conservation interventions. In order to investigate the impact of hunting on primates on Bioko Island, Equatorial Guinea, we collected data on primate abundance and hunting intensity across three areas in the Gran Caldera Scientific Reserve (GCSR) via reconnaissance surveys. We assessed how the relative abundance and proportional representation of Bioko's seven diurnal primate species varied among the different sites and in relation to hunting intensity. Overall primate species richness and abundance were highest in areas where gun hunting was minimal, but both measures declined with increasing evidence of gun hunting. Two species of primates, Cercopithecus erythrotis and Cercopithecus nictitans, were relatively tolerant of heavy hunting, but all other species were considered vulnerable. Procolobus pennantii, a species endemic to Bioko, exhibited the highest vulnerability, and its range appears restricted to a very limited area in the southwest of the GCSR. Our analyses indicate that hunting on Bioko is a strong contributor to current patterns of primate abundance and diversity, and suggest that hunting may be driving Bioko's most threatened primates (e.g., P. pennantii) towards extinction. These results highlight the need for rapid intervention on Bioko in order to safeguard the future of its unique primates.
Bioko Island, Equatorial Guinea is among the important places in Africa for the conservation of primates, but a cultural preference for bushmeat and a lack of effective law enforcement has encouraged ...commercial bushmeat hunting, threatening the survival of the remaining primate population. For over 13 years, we collected bushmeat market data in the Malabo market, recording over 35,000 primate carcasses, documenting “mardi gras” consumption patterns, seasonal carcass availability, and negative effects resulting from government intervention. We also conducted forest surveys throughout Bioko's two protected areas in order to localize and quantify primate populations and hunting pressure. Using these data, we were able to document the significant negative impact bushmeat hunting had on monkey populations, estimate which species are most vulnerable to hunting, and develop ecological niche models to approximate the distribution of each of Bioko's diurnal primate species. These results also have allowed for the identification of primate hotspots, such as the critically important southwest region of the Gran Caldera Scientific Reserve, and thus, priority areas for conservation on Bioko, leading to more comprehensive conservation recommendations. Current and future efforts now focus on bridging the gap between investigators and legislators in order to develop and effectively implement a management plan for Bioko's Gran Caldera Scientific Reserve and to develop a targeted educational campaign to reduce demand by changing consumer attitudes toward bushmeat. Using this multidisciplinary approach, informed by biological, socioeconomic, and cultural research, there may yet be a positive future for the primates of Bioko.
We summarize results from multifaceted primate conservation efforts on Bioko Island, detail the negative impact bushmeat hunting has had on primate populations, and discuss what strategies have worked and how we should move forward.
Mount Cameroon (4095 m), the highest peak and only active volcano in West Africa, is located in the center of the Gulf of Guinea Pleistocene refugium. The associated forests and highlands along the ...southern Nigerian-Cameroon border and on the island of Bioko, known as the Biafran forests and highlands, are important formations of the Cameroon Volcanic Line owing to their wide elevational range, and on Mount Cameroon, a continuous gradient of unbroken vegetation from sea level to over 4000 m. The montane zones in the region begin 800 m above sea level forming the critically endangered Mount Cameroon and Bioko Montane Forests ecoregion. The broad elevational gradient of the region has resulted in high habitat diversity, leading the region to be a center for species endemism and richness across many taxa. Some of the densest human populations in Africa also occur in this region, putting intense pressure on the forests and highlands mostly due to overexploitation and habitat loss. The governments of Nigeria, Cameroon, and Equatorial Guinea have designated protected areas in the region, but coverage is inadequate, especially for the rare montane ecosystems and endemic taxa. More importantly, protected areas are often not accompanied by effective management and regulatory enforcement. We recommend improved law enforcement and an expansion of the protected area network, as well as stronger commitments of institutional, financial, and technical support from governments and non-governmental organizations, in order to move conservation in the region in a positive direction. Without significant and immediate conservation progress, increasing anthropogenic pressure and systemic ineffectiveness of protected area management represent major concerns for the future of this important area.
Bioko Island's southern beaches are important nesting sites for marine turtles in the Gulf of Guinea region. In this study, we present data on the 4 species of sea turtles nesting on 5 nesting ...beaches (19 km) of Bioko Island, from 2000 to 2014. A total of 43,860 leatherback (Dermochelys coriacea), 16,778 green (Chelonia mydas), 1731 olive ridley (Lepidochelys olivacea), and 85 hawksbill turtle (Eretmochelys imbricata) encounters, defined as the number of tracks, were recorded on Bioko's southern beaches. Since 2008, the estimated number of leatherback females ranged from 42 to 444, green turtles from 63 to 649, and olive ridley turtles from 22 to 53 annually. This study presents the first extensive tagging program on Bioko Island, where 790 leatherback turtles were tagged with Passive Integrated Transponder tags from 2008 to 2014. Only 6.1% of the tagged turtles returned to nest again with a remigration interval of 3–4 yrs. In addition, 279 green turtles were flipper-tagged in the 2013–2014 nesting season. Overall, the total number of leatherback turtle encounters decreased annually from 2000 to 2014. These declines may be attributed to adult turtle captures in commercial fisheries operating in the Gulf of Guinea and turtle take in local artisanal fisheries. On the other hand, olive ridley encounters increased from 2000 to 2014. The construction of a paved road from Luba, the second largest city on Bioko Island, directly to the nesting beaches is now set to dramatically alter human interaction with nesting turtles. These long-term data confirm the importance of Bioko Island's nesting beaches for the Southeast Atlantic and fill a critical need for sea turtle conservation in a data-deficient, yet globally significant, area.
Africa's Gulf of Guinea, a major nesting ground for the critically endangered Leatherback Sea Turtle (Dermochelys coriacea), is experiencing rapid economic development. This study reports on the ...plasma biochemistry and packed cell volume (PCV) of turtles (55 samples collected from 23 individuals) nesting on Playa Moaba, Bioko Island, Equatorial Guinea. Because energy reserves and other resources in an individual are finite and turtles may not feed between nesting episodes, decreasing trends are expected in certain plasma biochemical concentrations and PCV values, as well as maternal investment in reproductive output (clutch size and egg mass). Calcium, potassium, sodium, phosphorous, plasma total protein, albumin, and globulin concentrations changed significantly with increasing number of nesting events, but remained within reported intervals in reptiles. Packed cell volume decreased significantly as the number of nesting events per individual increased. Although clutch size did not change, egg mass decreased significantly with increasing number of nesting events. The observed trends may be due to depletion of energy reserves and other resources during reproduction in a possible fasting state, and to the associated physiological stress.
Small organic molecules found on the skin of amphibians may help impart resistance to pathogens, such as the lethal fungus Batrachochytrium dendrobatidis. The study of these compounds has ...traditionally required euthanasia of the amphibian, followed by chemical extraction of excised skin. As an alternative method, we report the development and assessment of a non-lethal technique using foam-tipped swabs and HPLC analysis to directly isolate and characterize small molecules found on the skin of amphibians. This protocol was field-tested on Bioko Island, Equatorial Guinea with forty-seven frogs (representing 14 native species). Multiple species (particularly Afrixalus paradorsalisand Didynamipus sjostedti) carried sets of species-specific compounds (i.e., a chromatographic fingerprint). A principal coordinate analysis (PCO) of the commonly occurring compounds detected across all species revealed a significant relationship between chromatographic profile and species for all swab samples.
Bioko Island, part of Equatorial Guinea, has been classified as a critically important nesting site for sea turtles in the Gulf of Guinea. However, construction of a road through a previously ...undeveloped scientific reserve is set to dramatically alter human interactions with nesting turtle populations. This article reports on the current status of sea turtle conservation and research on Bioko Island as well as recent economic considerations that affect local turtle conservation and use.
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